Tadalafil in Subjects With Mild to Moderate Hypertension

Inclusion Criteria: * Have a documented medical history of hypertension. * Have cuff seated diastolic blood pressure values greater than or equal to 95 and less than or equal to 104 mm at study entry * Have a negative serum pregnancy test at the time of enrollment and agree to use two medically reliable methods of contraception until study completion, if female is of child-bearing potential, between menarche and 1 year post menopause and not surgically sterilized. * Are able to comply with study procedures and visits Exclusion Criteria: * Have resistant hypertension or systolic hypertension. * Are obese, defined as having body mass index (BMI) greater than or equal to 35. * Are females who are pregnant or breast feeding. * Have a history of severe renal insufficiency or significant thyroid, renal or hepatic disease. * Have a glycosylated hemoglobin A1c (HbA1c) greater than or equal to 10% during the screening period. * Have significant anemia. * Have a significant or unstable cardiac history such as history of heart attack, unstable angina, or stroke within 6 months of study entry, history of angina that was treated with long- or short-acting nitrates within 90 days of study entry, history of coronary artery bypass graft surgery or cardiac angioplasty within 90 days of study entry, history of abnormal heart rhythms such as sick sinus syndrome or 2nd- or 3rd-degree AV block, chronic atrial fibrillation or recurrent atrial tachyarrhythmia, a history of recurrent ventricular tachycardia, or symptomatic bradycardia, a history of sudden cardiac arrest. * Have symptomatic heart failure requiring treatment, or significant disease of the heart valves. * Have been treated for severe asthma, bronchospasm, or COPD within 3 months of study entry. * Have severe peripheral vascular disease. * Have a documented diagnosis of sleep apnea.